Portable recorder



Nov. 3, 1953 s. s. HAYNES 2,657,969

PORTABLE RECORDER Filed Dec. 2, 1949 2 Sheets-Sheet 1 INVENTOR. STEPHEN 5f MYNES QM Z ATTORNEY NOV. 3, 1953 5, s, H N 2,657,969

PORTABLE RECORDER Fi led Dec. 2, 1949 2 Sheets-Sheet 2 NVENTOR.

I STEPHEN 5. HA YNES @M ZM ATTORAEY Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE Bendix Aviation Corporation,

Baltimore, Md.,

a corporation of Delaware Application December 2, 1949, Serial No. 130,801

1 Claim.

This invention relates'generally to portable recording instruments of the type having at least one condition responsive pen cooperating with a moving chart to record the value-of the condition under observation and particularly to improvements of such a nature that permit low manufacturing cost, simplicity of operation, and a minimum of working parts.

An example'of the type of instrument to which the present invention is ideally adapted is a so-called portable hygrothermograph in which humidity and temperature responsive elements are arranged to actuate corresponding recording pens, the pens cooperating with a moving chart to record the value of humidity and temperature over a predetermined interval of time. Theentire assembly is housed within a portable carrying case, about the size of a camera, which can be conveniently carried in an overcoat pocket. The charts used with such an instrument are rectangular in shape and are conveniently designed for filing, being on the order of 3 x 5 inches. The chart derives its motion from a spring wound clock designed to give a maximum recording interval of thirty hours without re-winding of the spring.

The improvements covered by the present invention relate to the recording section of the instrument; namely, the chart-drive and the chart-carriage supporting andguiding arrangements.

It is desirable, in portable recording instruments, .to provide for more than one recording interval and, to this end, suitable sets of gears have been provided with such instruments. For example, if two chart speeds are required, it is necessary .to provide two sets of gears. Obviously, such an arrangement means that some provision must be made for storage of the alternate set of gears and consequently, space must be provided in the instrument for storage purposes. Furthermore, even with space provided for stor age, it is quite possible for :the alternateset of gears 'to be misplaced, which, of course, adds to the nuisance and inconvenience of handling several parts over a period of time.

Furthermore, it is desirable to have some means provided for quickly and easily moving the chart from its end point of travel to its initial position.

It is also desirable from the standpoint of compactness and ruggedness, tomake the overall recording assembly as simple and compact as is possible, utilizing a minimum number of parts, utilizing all available space, and accomplishing the above at the minimum cost.

Accordingly,'it isan object of th invention to provide, in a portable recording instrument, a novel two -speed driving mechanism, together with a novel arrangement for supporting the chart carriage, the entire assembly utilizing a minimum number of parts, making effective use of available space, and being adapted for lowcost manufacture.

Other objects and advantages will be apparent upon reference to the detailed specification following, when taken in conjunction with the drawings annexed hereto, in which:

Fig. 1 is a front view, in elevation, of a portable recording instrument, wherein portions of the instrument have been cut away to show the novel two-speed driving mechanism.

Fig. 2 is a side-view of the instrument shown in Fig. 1, there being a portion of the housing cut away.

Fig. 3 is a somewhat exploded view of the novel two-speed gear assembly shown in Fig. 1, but with the parts arranged for a diiierent driving speed.

Fig. 4 is a back view of the carriage shown in Fig. 1, the supporting plate cooperating with the carriage being shown in phantom lines.

Fig. 5 is a partial sectional view along the lines 55 of Fig. 1.

Referring now to Fig. 1, we see a portable recording instrument 6 which, in this case, is a hygrothermograph having a pair of recording pens 7, 8, the pens moving in response to changes in ambient temperature and humidity, respectively. Suitable temperature and humidity responsive devices are mounted within the instrument 6, together with suitable mechanical linkage systems for actuating the pens l, 8. The condition responsive devices and the linkage system form no part of the present invention and, for the sake of brevity and clarity, have not been shown in the drawings. The instrument 6 consists of a two-part casing having a front section 9 and a back section II, the two sections being hinged together on one side as shown at l2, there being a suitable latch (not shown) on the side opposite the hinge for retainingthe sections together. A suitable handle i3 is provided for conveniently carrying the instrument.

There is also a window M in the front section 9 to permit inspection of the chart without opening the instrument. The window M may be of the type shown in co-pending application Serial No. 115,544 filed September 13, 1949.

A carriage assembly [5 is provided for moving 3 a chart (not shown) through a predetermined distance corresponding to a predetermined time interval, with respect to the recording pens l, 8, so that a visual record of ambient temperature and humidity is produced.

The carriage i5 is mounted for movement along a vertical plate IS, the carriage being provided with a pair of flanged wheels ll, 53, and a third wheel IS, the wheels being adapted to roll along the edges 2! and 22, respectively, of the plate U5. The plate 53 is suitably sup ported within the instrument 55 by means of a pair of flanged members 23 (one of which is shown in Fig. 2), each one of the flanged members, in turn, being suitably secured to the upper and lower surfaces of the back section H, respectively. The plate I6 may be secured. to the flanged members 23 by means of suitable screws.

Wheels l! and it are suitably mounted for rotation directly on carriage l5, whereas wheel !9 is carried on one end of a lever 24, pivotably mounted at on the carriage [5, the other end of the lever 24 having one end of spring 23 affixed to pin 2?, which. in turn, is siutably secured to the carriage iii. The spring 33 biases the lever 24 in a direction urging the wheel I9 in engagement with edge 22.

Each of the wheels l1, l8 and I3 is identically made and its manner of construction can be readily seen by reference to Fig. 4, wherein the wheel I! is shown with portions of it cut away to illustrate the mode of construction. Referring specifically to Fig. 4, it is seen that the edge engaging portion has a flange affixed to each of its ends and the flanges serve to guide the wheel along the edge.

With the above-described arrangement, it is apparent that the carriage l5 can travel up and down on the plate I G with a minimum amount of possible lateral motion. It is not necessary that the edges 2!, 22, be absolutely parallel, nor is it necessary that the width of the plate I 3 defined by these edges be held to close tolerances, as the resilient mounting of wheel I!) will compensate for minor deviations. An important ad vantage is derived from this arrangement in that manufacturing costs are materially reduced by eliminating the necessity of maintaining the edges 2!, 22, in precise spaced parallel relation ship. Another important advantage is also olerived from the resilient mounting arrangement of the Wheel [9, and this will be described later A gear 23, extending through opening 29 in the plate I3, is driven by means of a conventional spring-wound clock motor generally indicated at 3! (see Fig. 2), secured within the back section I! of the instrument 6 on the back side of the plate 13. The clock motor 3! has a winding stem 32 and a setting stem 33, the stems extending through the back face of the back section i! for convenient manipulation. The gear 7.3 constitutes the driving gear.

An integral assembly 34 of a pair of gears 35, 3B, is also journaled for rotation in the plate It and is adapted to engage with the gear 23. The integral gear assembly 34 is also adapted to engage the pinion 3'], which is journaled for rotation. in the plate It, the pinion 31, in'turn, engaging the rack 33, which is afiixed to the rear face of the carriage assembly I5.

Thus it will be seen that the clock 3| drives the gear 28 and, by means of the integral gear assembly 34, the pinion 3! is driven; which, in turn, drives the rack 38 to move the carr g assembly IS with respect to the recording pens 1, 8.

The integral gear assembly constitutes one or the novel features of the invention and consists of the gears 35, 36, arranged concentrically about a common center, the two gears having different radii. Referring now to Fig. 5, we see that the gear 35 is in the form of a pinion having a suit-- able hub 39, which is adapted to be pressed into a centrally located aperture in the gear 35. Thus, the gears 35, 36, are rigidly secured together to comprise an integral gear assembly.

The gear 36 has an aperture 4| located centrally thereof and the aperture 4! is cutaway at its extremities to form the annular shoulders 42, 43. A screw 44 having an enlarged head 45 extends through the aperture 4| with the head 45 nesting in the annular shoulder 42, and its threaded extremity 45 extending beyond the hub 33. A pair of threaded apertures 41, 48 (see Figs. 1 and 3) are provided in the plate l6 for selectively receiving the threaded extremity 45 of the screw 44. A slot 49 is provided in the head 45 so that the screw 44 can be conveniently as sembled or disassembled by means of a screwdriver.

In the position of the assembly shown in Fig. l, the gear 35 engages both the driving gear 223 and the pinion 3?, whereby a direct drive is provided from the driving gear to the pinion, resulting in a slow speed of the carriage assembly l5. In this position of the parts, the gear 35 serves as an idler gear.

If it is desired to move the carriage assembly !5 at high speed, it is only necessary to remove the screw 44 from the aperture 41 which, of course, permits the gear assembly 34 to be removed. To reassemble to the high-speed operation, the gear assembly 34 is merely turned over and the screw 44 is inserted through the aper ture 4! in such a fashion that the head 45 nests in the shoulder 43. With the screw 44 and the gear assembly 34 in this position, the threaded extremity 46 of screw 44 is inserted into the threaded aperture 43 and the screw 44 is tightened in place. Such a position of the parts as sembled for high-speed operation is shown in Fig. 3. In this position, the gear 35 engages the driving gear 28 and the gear 35 engages the pinion 31. It is to be noted (see Fig. 2) that the gear engaging surface of the pinion 31 is sufflciently wide to permit engagement of the pinion 31 with the gear 35 in both positions of the integral gear assembly 34. Again referring to Fig. 3, it is obvious that the gear 35 will now rotate faster than when in the position shown in Fig. 1, thus resulting in a higher speed drive for the carriage assembly l5.

From the above, it is evident that two speeds of operation are provided for the carriage assembly l5 by means of the novel assembly of the gears 35, 35. No spare or alternate sets of gears are required, which, of course, eliminates any need for storage space for such an alternate or spare set of gears, and permits a maximum use of the effective space within the housing of the instrument 6. All of the parts required for the two-speed operation are constantly in use and the mechanism can be readily adjusted for one speed or the other through the simple expedient of removing the screw 44, reversing the position of the gears 35, 56, and reinsertion of the screw 44 into the alternate apertures provided in the plate l6.

The design of the instrument shown is such that, when the parts are assembled as shown in Fig. 1, the carriage assembly !5 will move through a distance corresponding to an interval of thirty hours, whereas, with the parts assembled as shown in Fig. 3, the carriage assembly 15 will move through the same distance as before but the distance, in this case, will correspond to an interval of ten hours. Thus we have a three-to-one ratio of driving speeds for a constant speed clock motor. Suitable stop pins 5| are ailixed to the plate [6 near its upper and lower extremities (only the lower pin showing in the drawings-see Fig. 1) for limiting the travel of the carriage 15 in a vertical direction. The bottom pin 5i is shown opposite the U-cutout in rack 33, so that the carriage l5 can move to the bottom of the instrument.

In operation, a chart is suitably secured to the carriage 15, by means cf pins 52, 53, and the spike 5d, and the carria e is positioned at its upper limit of travel. Each of the pins 52, 53, have an enlarged head and are adapted to cooperate with holes in the chart, each of the holes having a small slot extending therefrom,

the width of which is substantially the same as the width of the pins 52, 53. Thus the chart can be positioned by matching the holes on the chart with the enlarged heads of the pins 52, 53, and then sliding the chart with respect to the pins so that the portion of the pins of reduced diameter finally engages the slot portions of the holes in the chart. The spike 54 extends from the face of the carriage l5 and pierces the chart to further secure same in place.

The gear assembly 3 is positioned as required,

after which the clock 3| can be wound, and the instrument will then record continuously until the carriage assembly l5 reaches the lower limit of its travel. Again referring to the resilient mounting of wheel 19, it is apparent that the carriage I 5 can be moved up or down, at will, for adjustment purposes, merely by pressing firmly on the edge of the carriage 15 adjacent the wheel l9. Such pressure permits transverse motion of the carriage 15 of sufiicient magnitude to disengage rack 38 from pinion 31 and thus permit free vertical motion of the carriage. In this connection, the pin 21, together with stop pin 55, limits transverse motion of the carriage so that the flanges of the wheels i1, beyond the edge of the plate 16.

It is to be noted that disengagement of the rack 38 from the pinion 31 will permit adjustment of the vertical position of the carriage l5.

However, this adjustment of the position is relatively coarse in that the width of the teeth of the rack 38 is a limiting factor. Fine adjustment of the position of the carriage i5 is achieved by means of the setting stem 33 of the clock 3|. The coarse adjustment is quick and permits the carriage to be adjusted to the approximate position desired and the setting stem, which comprises a manual drive for the gear 253, permits the final position to be adjusted quite closely. Thus another important advantage is attained through the use of the resilient mounting of wheel ill, for, in the absence of such an arrangement, it would be necessary to resort solely to the setting stem 33 for positioning of the carriage I5. Obviously, such an arrangement would be laborious and time-consuming for any substantial range of adjustment of the carriage l5.

18 do not project 2141 From the above, it will be seen that a twospeed recording mechanism is provided embodying a minimum number of parts, a reduction in space requirements, and minimum manufacturing costsall these advantages being attained through no sacrifice in accuracy or precision.

What is claimed and desired to be secured by United States Letters Patent is:

In a portable recording instrument of the type having at least one condition responsive pen cooperating with a chart moving in a vertical direction to record the value of a condition under observation, in combination: a vertically extending main support plate having a pair of substantially parallel vertical edges, a carriage for supporting said chart, means afiixed to said carriage and cooperating with said edges to permit said carriage to move with respect to said plate in a vertical direction, said. last named means comprising a first pair of flanged wheel rotatably mounted on said carriage and engaging one of said edges and a third Wheel rotatably mounted on said. carriage and engaging the other of said edges, said third wheel being mounted on a lever arm, said lever arm being pivotally mounted on said carriage and biased in a direction urging said third wheel against said other edge, said third wheel being adapted for limited motion in a direction tranverse to said edges, and means for moving said carriage, comprising a rack afiixed to said carriage, a pinion engaging said rack and rotatably mounted on said plate. a two-speed gear for driving said pinion, a clockdriven gear for driving said two-speed gear, a clock mechanism mounted on said main support plate and having its drive-shaft extending through an aperture in said support plate so that said clock-driven gear can be afixed thereto, said two-speed gear comprising a pair of integral gears having different radii arranged about a common center, and means for selectively mounting said two-speed gear for rotation about alternate axes in said plate whereby, in one position, the larger of said gear pair engages said pinion and said clock-driven gear and, in the other position, the larger of said gear pair engages said pinion and the smaller of said gear pair engages said clock-driven gear, said last named means comprising a pair of spaced threaded apertures in said plate, an axially located aperture in said two-speed gear, and a screw cooperating with said axial aperture to permit rotation of said two-speed gear, said screw selectively engaging either of said pair of apertures in said plate.

STEPHEN S. HAYNES.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 442,925 Tanner et a1. Dec. 16, 1890 ,069,594 Wurmb et al. Aug. 5, 1913 1,944,672 Schaefier Jan. 23, 1934 2,033,177 Borden Mar. 10, 1936 2,181,867 Cameron Dec. 5, 1939 2,351,921 Bullard June 20, 1944 2,389,345 Dell et a1. Nov. 20, 1946 FOREIGN PATENTS Number Country Date 594,954 Great Britain Nov. 24, 1947 

